[PATCH RFC 0/4] Fix orion-mdio resource/interrupt issues indentified while reviewing mvpp2

[PATCH RFC 0/4] Fix orion-mdio resource/interrupt issues indentified while reviewing mvpp2

[Russell King - ARM Linux]

This patch series fixes some issues identified while reviewing the
mvpp2 driver changes recently posted by Thomas.  I've left the clock
issue, and the question over whether this should be separate out of
this series, concentrating on the resource size / interrupt issue.

This series updates the binding to reflect reality, and ensures that
the driver will not try to access registers outside its binding.  It
also ensures that it doesn't leave the interrupt enabled in hardware
on probe failure.

 .../devicetree/bindings/net/marvell-orion-mdio.txt      | 17 +++++++++++++++--
 drivers/net/ethernet/marvell/mvmdio.c                   | 11 ++++++++++-
 2 files changed, 25 insertions(+), 3 deletions(-)

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.

[PATCH RFC 1/4] net: mvmdio: disable interrupts in driver failure path

[Russell King]

When the mvmdio driver has an interrupt, it enables the "done" interrupt
after requesting its interrupt handler.  However, probe failure results
in the interrupt being left enabled.  Disable it on the failure path.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/net/ethernet/marvell/mvmdio.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/marvell/mvmdio.c b/drivers/net/ethernet/marvell/mvmdio.c
index a0d1b084ecec..7aea0beca56e 100644
--- a/drivers/net/ethernet/marvell/mvmdio.c
+++ b/drivers/net/ethernet/marvell/mvmdio.c
@@ -251,6 +251,8 @@ static int orion_mdio_probe(struct platform_device *pdev)
 	return 0;
 
 out_mdio:
+	if (dev->err_interrupt > 0)
+		writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
 	if (!IS_ERR(dev->clk))
 		clk_disable_unprepare(dev->clk);
 	return ret;
-- 
2.7.4

[PATCH RFC 2/4] net: mvmdio: fix interrupt disable in remove path

[Russell King]

The pre-existing write to disable interrupts on the remove path happens
whether we have an interrupt or not.  While this may seem to be a good
idea, this driver is re-used in many different implementations, some
where the binding only specifies four bytes of register space.  This
access causes us to access registers outside of the binding.

Make it conditional on the interrupt being present, which is the same
condition used when enabling the interrupt in the first place.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/net/ethernet/marvell/mvmdio.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/marvell/mvmdio.c b/drivers/net/ethernet/marvell/mvmdio.c
index 7aea0beca56e..6ea5caddca62 100644
--- a/drivers/net/ethernet/marvell/mvmdio.c
+++ b/drivers/net/ethernet/marvell/mvmdio.c
@@ -263,7 +263,8 @@ static int orion_mdio_remove(struct platform_device *pdev)
 	struct mii_bus *bus = platform_get_drvdata(pdev);
 	struct orion_mdio_dev *dev = bus->priv;
 
-	writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
+	if (dev->err_interrupt > 0)
+		writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
 	mdiobus_unregister(bus);
 	if (!IS_ERR(dev->clk))
 		clk_disable_unprepare(dev->clk);
-- 
2.7.4

[PATCH RFC 3/4] dt-bindings: correct marvell orion MDIO binding document

[Russell King]

Correct the Marvell Orion MDIO binding document to properly reflect the
cases where an interrupt is present.  Augment the examples to show this.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 .../devicetree/bindings/net/marvell-orion-mdio.txt      | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/marvell-orion-mdio.txt b/Documentation/devicetree/bindings/net/marvell-orion-mdio.txt
index 9417e54c26c0..ca733ff68ab9 100644
--- a/Documentation/devicetree/bindings/net/marvell-orion-mdio.txt
+++ b/Documentation/devicetree/bindings/net/marvell-orion-mdio.txt
@@ -7,7 +7,10 @@ interface.
 
 Required properties:
 - compatible: "marvell,orion-mdio"
-- reg: address and length of the SMI register
+- reg: address and length of the MDIO registers.  When an interrupt is
+  not present, the length is the size of the SMI register (4 bytes)
+  otherwise it must be 0x84 bytes to cover the interrupt control
+  registers.
 
 Optional properties:
 - interrupts: interrupt line number for the SMI error/done interrupt
@@ -17,7 +20,7 @@ The child nodes of the MDIO driver are the individual PHY devices
 connected to this MDIO bus. They must have a "reg" property given the
 PHY address on the MDIO bus.
 
-Example at the SoC level:
+Example at the SoC level without an interrupt property:
 
 mdio {
 	#address-cells = <1>;
@@ -26,6 +29,16 @@ mdio {
 	reg = <0xd0072004 0x4>;
 };
 
+Example with an interrupt property:
+
+mdio {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	compatible = "marvell,orion-mdio";
+	reg = <0xd0072004 0x84>;
+	interrupts = <30>;
+};
+
 And at the board level:
 
 mdio {
-- 
2.7.4

[PATCH RFC 3/4] dt-bindings: correct marvell orion MDIO binding document

[Mark Rutland]

On Sat, Jan 07, 2017 at 11:28:30AM +0000, Russell King wrote:
> Correct the Marvell Orion MDIO binding document to properly reflect the
> cases where an interrupt is present.  Augment the examples to show this.
> 
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

This looks fine to me.

Acked-by: Mark Rutland <mark.rutland@arm.com>

Mark.

> ---
>  .../devicetree/bindings/net/marvell-orion-mdio.txt      | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/marvell-orion-mdio.txt b/Documentation/devicetree/bindings/net/marvell-orion-mdio.txt
> index 9417e54c26c0..ca733ff68ab9 100644
> --- a/Documentation/devicetree/bindings/net/marvell-orion-mdio.txt
> +++ b/Documentation/devicetree/bindings/net/marvell-orion-mdio.txt
> @@ -7,7 +7,10 @@ interface.
>  
>  Required properties:
>  - compatible: "marvell,orion-mdio"
> -- reg: address and length of the SMI register
> +- reg: address and length of the MDIO registers.  When an interrupt is
> +  not present, the length is the size of the SMI register (4 bytes)
> +  otherwise it must be 0x84 bytes to cover the interrupt control
> +  registers.
>  
>  Optional properties:
>  - interrupts: interrupt line number for the SMI error/done interrupt
> @@ -17,7 +20,7 @@ The child nodes of the MDIO driver are the individual PHY devices
>  connected to this MDIO bus. They must have a "reg" property given the
>  PHY address on the MDIO bus.
>  
> -Example at the SoC level:
> +Example at the SoC level without an interrupt property:
>  
>  mdio {
>  	#address-cells = <1>;
> @@ -26,6 +29,16 @@ mdio {
>  	reg = <0xd0072004 0x4>;
>  };
>  
> +Example with an interrupt property:
> +
> +mdio {
> +	#address-cells = <1>;
> +	#size-cells = <0>;
> +	compatible = "marvell,orion-mdio";
> +	reg = <0xd0072004 0x84>;
> +	interrupts = <30>;
> +};
> +
>  And at the board level:
>  
>  mdio {
> -- 
> 2.7.4
> 

[PATCH RFC 3/4] dt-bindings: correct marvell orion MDIO binding document

[Rob Herring]

On Sat, Jan 07, 2017 at 11:28:30AM +0000, Russell King wrote:
> Correct the Marvell Orion MDIO binding document to properly reflect the
> cases where an interrupt is present.  Augment the examples to show this.
> 
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
> ---
>  .../devicetree/bindings/net/marvell-orion-mdio.txt      | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)

Acked-by: Rob Herring <robh@kernel.org>

[PATCH RFC 4/4] net: mvmdio: disable interrupt if resource size is too small

[Russell King]

Disable the MDIO interrupt, falling back to polled mode, if the resource
size does not allow us to access the interrupt registers.  All current
DT bindings use a size of 0x84, which allows access, but verifying it is
good practice.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/net/ethernet/marvell/mvmdio.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/marvell/mvmdio.c b/drivers/net/ethernet/marvell/mvmdio.c
index 6ea5caddca62..614dfde657fe 100644
--- a/drivers/net/ethernet/marvell/mvmdio.c
+++ b/drivers/net/ethernet/marvell/mvmdio.c
@@ -221,6 +221,12 @@ static int orion_mdio_probe(struct platform_device *pdev)
 		clk_prepare_enable(dev->clk);
 
 	dev->err_interrupt = platform_get_irq(pdev, 0);
+	if (dev->err_interrupt > 0 &&
+	    resource_size(r) < MVMDIO_ERR_INT_MASK + 4) {
+		dev_err(&pdev->dev,
+			"disabling interrupt, resource size is too small\n");
+		dev->err_interrupt = 0;
+	}
 	if (dev->err_interrupt > 0) {
 		ret = devm_request_irq(&pdev->dev, dev->err_interrupt,
 					orion_mdio_err_irq,
-- 
2.7.4